Main's in big (home :) control room

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Hello everyone! Esteemed Ladies & Gentlemen, I am glad to welcome your's experience and indulgent relation to eager for the help :)

I'm some novice on this forum, but i found here so many interesting for me information, and so, now it's time to build my own thread about... About some crazy russian studio perfomance, for example:eek::eek:

So... I'm one of homelike producers - love to play different eclectic music, record live-improvised sessions and other other etc, include post-production, mixing, sometimes mastering (who, if not I::confused::D). Not commercial, just only from my big love to soundart.

And nowadays, i'm going to levelup my controlroom abilities. Way so long, hard and thorny, but have no choice :)

How i see "sucessful end result ": It's full-ranged 3 or 4-way system, rather analytical and transparent to do "home mastering missing", and other mixing tasks.

What about i can to enclose in it:

Room Size: 4.9x7.8m. (38m^2 between massive walls) What about height... So, because it's my own house (second floor exactly), i've made a "sound-transparent" ceiling. Room's walls have a 2.8m height, and than, no reflection surface :eek: (only 20cm rockwool + furnishing fabric), connect control room with a attic-floor room (about 10x10m, with a 1.5-2.5m between floor and roof (metallic tile).
May be it's hard to understand and imagine, but i attach a photo, that can to facilitate this moment :)

So, the main thing about so many "mine letters about room:rolleyes:":
that we have great area with a giant volume of air below the ceiling (if I start talk about metallic tile reflection ability... Hmm... Theoretical on low frequency signal we haven't ceiling at all:D

What about acoustic preparation - don't have problems with it, and I will try to made "reflection-free control room".

Speakers...
I think, that will be required many-many watts of amplification and woofers to create a necessary stock of power, necessary to "easy and sure undistorted working on a 95 dB in a sweetspot". Don't wanna go to ProAudio gig's SPL, but found "golden measure" between watts&meters not so easy :) And, of course, in priority - high monitoring audio quality.

Nowadays, I use pair of Adam A8X and TransmissionLine QuaterWave-subwoofer tuned on a 32 Hz on a 18Sound 18LW1400. (Big heavy painful:)

Main problem, that i have today - 8.5" woofer have some problems on a 1-2 kHz. And small Heil doesn't work stable&fine on a big SPL, because 2300 Hz crossover frequency...) The slightly failed mids, so sad(( (Needed more mid-frequency ribbon))

Looking forward to a close day, in which I move to new room (that i describe above), i think, will have some problems in midbass, because:

1)Area&Volume is so big to get what i want from i have.
2)Room size: Have compromise in monitors location: Good Stage or flat AF response.

I will prefer to place A8X close to me, to get great soundstage image, and transfer 70-200 Hz to a separate "midbass section" (for example 12" on a side), that can be InWall sofit mounting or have another midfield position further than Adam's.

And so, 30-70 Hz we can move to 18". Two 18". Many 18" in Infinite Buffle - we will go all the way.
(have one empty 12m^2 room for that:D:D)

If you read up until this moment - thank you, for you great interest in my modest life of underground mixing engineer. :)

I can formulate my main question on this moment:

1)What should i do, to be ABSOLUTELY sure, that my DIY transmission-line subwoofer working transparent and analiticaly, because i try to use it in mixing/mastering mission's? Room Eq Wizard can help me to understand what's going on:)
2)Can I independently measure TC parameters of my unnamed vintage 12" speakers with a adequate accuracy, to build them correct midbass acoustic design (thinking about horns horns horns :))? May be you can direct me to a true way, how doing this...
3)May be downgrade from A8X to A5X is good idea to get better "upper mids"?
3)And what, in general, about my view of control room? A8X in close nearfield + 2x12" in horns Inwall or separate location + 2x18" TL Subs (or IB... Question of subs will be solved in the last turn)

Thank you for attention, hope that we have much fine in founding a solution... :)
 

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Thinking about Scanspeak Discovery 10F/8424G 4" Midrange 8 ohm
to get it right between A8X's twitter and 8.5" woofer (the same, Discovery series, how I understand).
Crossovering and can go hell's hard, but, seems to me, that adding a 4" in middle is necessary measure for the movement the designated direction.

So, am i crazy?...
 
So... Going in 4-way:

HF: Fountek Neo x 2.0 ribbon (may be go to horn design)
MF: Coral MD-5 dome 3"
LMF: Eton A1-160 Adventure 6.5"x2 on side. (Hello caraudio!:) Closed box 13l + digital correction. In Future, may be added fift's Eton to a front horn-monomidbass module (have 5 speakers and 5-channel amp. lol:)
All 3-way in box in nearfield.

LF: Alphard LW120A4 in big closed box with correction. May be inwall in front. Goes to 50-(200-300) Hz. So, it sounds midfield.

SW: Obsidian OA18 (4+4) in a 32-hz tuned quarter-wave TL.

Here you can found some TSP on drivers: https://yadi.sk/d/MaponoQqsv5Jx (for Coral dome have no information, but have a catalogue with it)

Amplification and filters:

HF&MF seems to have passive crossover, and nowadays I have no respectable amplifier for them. (May be you can advice, what i should try to find?)
LMF have active filtration and Rotel RB-985 Mk II. (~175 w / 4ohm / 5 channel) One driver=one amplifier channel...
LF have active filtration too and Inter-M M1000 (500w / 4 ohm / 2 channel)
SW, of course, digitally crossovered and TCM-6002 (1200w/ 4ohm / 2 channel).

Digital philters and all other sound processing provided via VST plugins in Reaper. (Motu Audio Express Hardware)
In foreseeable future going to achieve miniDSP Open DRC DA-8, it will be such pretty to use only SPDIF on my soundcard :)

that's all. Welcome to criticism and councils!
 
Could you post a dimensioned sketch of your room, speaker positions, and main listening position? This will help decisions on polar pattern, and desirable room changes. There are several websites with good information on building and setting up a recording studio using modern DSP with controlled directivity speakers. Forums on home studios often discuss how to DSP custom-tune the speaker SPL based upon target ambience, target audience, target play back equipment(ear phones, MP3, audiophile)

Typical Controlled Directivity Speaker Parts.
-Reduce wall+ceiling short delay bounce.
-Polar patterns crossed in front of listener.
-SEALED 18” woofer(s) with DSP for equalization and SPL tuning (20-140Hz)
-SEALED 10” midbass with DSP for equalization and SPL tuning (140-1400Hz) most of vocal range
-Horn like H290C from Pi-Speakers($50) + 1” CD (1600Hz) passive or DSP Xover
-DSP with 2 or 3 amps

Recording Studio Design 101: How to Set Up Your Room
John Sayers' Recording Studio Design Forum • Index page
 
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When you setup your speakers/monitors and mixing console, may want to take into account the Allison effect, ie try to avoid symmetrical distances to any hard surface. It makes everything non symmetrical, but gives better sound as the peaks and dips are spread out.


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Have you spoken with GIK Acoustics?

If these about room acoustical design - it's not a problem, I have some expirience in building LEDE control room, so, i think, my multy-way speakers will have minimal exact room intervention. (i'm talking about 3-way in nearfield).


Could you post a dimensioned sketch of your room, speaker positions, and main listening position?

Of course... Some writings in mspaint :))

I don't point acoustical absorption on my picture. Going for Philip Newell conception, and think that about 0.5-0.8 meters receding around the walls will be used for acoustic preparation of my room. Of course :)

Front wall needs more attention - i can cut corners to provide better room response and use this volumes for midbass section. Or subs :)(You can see example in purple on picture).

based upon target ambience, target audience, target play back equipment(ear phones, MP3, audiophile)


May be:) But first and main purpouse - get an very analytical and honest studio monitoring. Without hi-fi coloring.

When you setup your speakers/monitors and mixing console, may want to take into account the Allison effect, ie try to avoid symmetrical distances to any hard surface.

It takes 2-3 years, to finish acoustical preparation and building of mine monitor system... So, i know about SBIR-effect much more, and will make more efforts in a battle with reflections :)

Main question is about mine set of drivers and acoustical design, including questions of crossover and tune all this into one :))

Thank for answers and advices!
 

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If the point is a good quality mastering studio you should probably focus on implementing readily available knowledge and not venture into reinventing the wheel by a new speaker design. that's all been figured out by people who spent many years on constant directivity etc. check out Earl Geddes and Linkwitz designs (I experienced both and have the latter at home), as well as commercial monitor offerings. getting the bass right and room treatment is the biggest challenge. I managed to integrate a sub very successfully at my home owing to a highly irregular shape space; and really only for a close range of listening volumes. others in more conventional rooms use bass traps and similar to help the situation. for the best results all active approach and DSP is assumed.
 
If you research corner speaker placement you may find their constant directivity desirable for the "neutral presentation" valued in a recording studio, plus the potential for smooth full-room bass from putting DSP equalized woofers in all four corners. Your dedicated room allows non-intrusive large(8cuft) corner volumes for great transienst from DSP sealed 18" woofers.

You could construct removable sealed TM tops (with 90H x 40V tweeter horns) that cover down to ~80Hz to provide in-room placement options for more ambience from diverse wall-floor reflections. Pull the TM sealed cabinet from its corner slot for close listening.

==================
If you decide to construct a floor standing TM-W sealed box speaker, consider a horn tweeter to reduce side wall and floor reflections. 90-degree horizontal horn can cover a listening couch. 60-degree horizontal horn aims sonic details to one.

===============
Earl Geddes Directivity paper.
PiSpeakers Constant Directivity paper.
Woofer room placement papers will include 4-corner measurements.
 

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"Optimum Room Locations for Subwoofers An Analysis by Todd Welti — October 22, 2014" simulates a few popular multi-woofer in-room placements across over 30,000 different size/shape listening rooms and summarizes the data. (pic of configs)

Subs in four corners (4C) performs well for SC = Small Center Audience. I attached his summary table and a bass SPL map for four corner woofers over his 30,000 simulation points. (pics)

Corner woofer placement excites all possible room modes, resulting in a denser standing wave pattern in the room. This reduces, but doesn’t eliminate, the potential to encounter nulls, which are acoustic cancellation points or 'dead spots’ in the room. (pic of SPLs)
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I ran a no-delay + no-boost REW simulation of your room dimensions with four-corner woofers which looks pretty good as long as:
1) HEAVY absorption material is on the rear wall; (A rear diffuser will help smooth high freqs)
2) modest absorption material is on the side walls and floor.

------------
If you construct 3-way TM-W corner speakers, I would build a separate sealed TM box which can be pulled from the corner and positioned in the room a few feet away from all walls to generate extra "ambience" from short delay wall-reflected high frequencies. A 90H x 40V horn is common for corner speakers, so room reflections will still have some control.

Several 10" or 12" midbass can reach F3 ~60Hz in under 2cuft sealed cabinet. Several AES papers show that ~60Hz physical woofer placement cannot be detected.
 

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Now, it's time to make a first step - sub location in a room.
4Corners solutions looks very pretty, but i have only one 18" Transmission-Line, and, have no need in a Large Listening Position. And Have no way to get MOORE SUBS.

It looks like
An externally hosted image should be here but it was not working when we last tested it.


But nowadays i placed it on a side, because this way it makes less intervention in room acoustic. (Size: Width/Depth/Height 1/0.95/0.53 meters).

Its a TL, tuned to 32hz, with a 1/3 wave shift (0.9m from driver to closed end of line, 1.8m from driver to open port. Driver's TSP: https://yadi.sk/d/_U4VHTtevSzzL

When it placed near frontwall, it can reach 25Hz at -3db in a listening position (2meters from subwoofer buffle to sweet listening spot).
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And when we talk about
getting the bass right and room treatment is the biggest challenge.
:
Can say, that:
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An externally hosted image should be here but it was not working when we last tested it.



Hmm. Non-reflective ceiling is amazing. And, when i play my bassguitar, tuned to C=33 hz, it really feels like measured in REW waterfall, so short...


I ran a no-delay + no-boost REW simulation

Think, it's not a good idea, because my celling not symmetrical, and I can't say anything about reflection possibility of a metal tile roof. Some pictures for understanding:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


Simulations useless, only moving with a REWing...

I've driven by idea, that sub should be as far away from listener, as room allows. Because it can achieve maximum SPL at lowerest frequency. So, when i get ready to move this 100kg of damn sawdust in glue, try to place sub at middle of rearwall. What you think about it?
Even i can move sub to one of rear corners, but in this case room will be more assymertrical and i will have rooms or windows in direct near subwoofer. So middle is more preferred position.

You could construct removable sealed TM tops (with 90H x 40V tweeter horns) that cover down to ~80Hz to provide in-room placement options for more ambience from diverse wall-floor reflections. Pull the TM sealed cabinet from its corner slot for close listening.

I think about 3-way tops (separated from mids and sub), that cover down to 150-200 Hz. Placed at about 1.5m from listener's position (I've drawed it in a previous messages).

consider a horn tweeter to reduce side wall and floor reflections. 90-degree horizontal horn can cover a listening couch. 60-degree horizontal horn aims sonic details to one.

My walls in ERZ have great absorption right from ~250 Hz (its today, but in future i try to make a lower absorption), so, does I need horn twitters? Walls walls... but i have table surface and 2 displays right near TM tops,
An externally hosted image should be here but it was not working when we last tested it.


is it reason to think, that horn twitters are more preferable?

Several 10" or 12" midbass can reach F3 ~60Hz in under 2cuft sealed cabinet.

Midbass... For 60-200 Hz I have 12" Alphard LW120-A4. TSP: https://yadi.sk/d/deb7x6KrvTCru

Think about ~7 cuft sealed "slim" boxes. Slim means that size should be: W/D/H: 0.75/0.3/1m. It's so close to "Inwall", but separately with an main front wall (important to sound insulation).

I have an idea, trying to made a deadlock transmission line (of course with a 1:1.6 sides that make an Sd) into this sealed boxes and do the stuffing to best absorbtion the rearside diffusor energy. What you think about it?

May be, in future, i will turn this boxes to normal TL's, if needed. But I should start from sealed.

Picture about placement all of:
An externally hosted image should be here but it was not working when we last tested it.



If I try to realize "really in-corner driver placement" like in a:
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My listening position will go from perfect 38% of lenght, to an doubtful middle of a room. I will repeat - don't need large listening area, much more important - have the weakest early reflections (because speakers are nearer) and smoothed low's SPL.

I can leave listening position on the 38%, but in this case, general axis (green line at my picture) will be broken, my triangle will become non-equilateral, and i need to correct mids stereo width (it's so easy, because have separate amplification, but how correct it should work?..).

Or, you think, that in-corner midbasses placement should give best results, despite the "reasons", i've stated above? Not so sure in what i'm saying:) So, hope that you will treat calmly :):confused::innocent:

Thank for attention! Your's answers are really important to my work.
Best Regards.
 
My room sketches assumed you would invite small groups of musicians or customers or friends to work over the sound-mix with you. I assumed this room would naturally evolve into a small group home theater.

For your smaller listening area I only have one suggestion: for the best quarter-wave coherence put your 12" drivers directly under(next to) the satellite speakers to create a 3-way source which produces bass below 60Hz with DSP. A 200Hz sine has a 17" quarter wavelength, so keeping the 12" drivers next to the satellites will improve direct and reflected sound coherence around the room.
 
I assumed this room would naturally evolve into a small group home theater.

Sounds cool. Of course, I'll take some expiriement with a satellite's position, moving them right to corners, but, seems to me, moving speakers far from me not so good idea... More room reflections in a final sound, and less deep soundstage.
Or, am I mistaken, and early reflecting sound (if speakers are in-corner) doesn't do problems to an listening?

for the best quarter-wave coherence put your 12" drivers directly under(next to) the satellite speakers to create a 3-way source which produces bass below 60Hz with DSP. A 200Hz sine has a 17" quarter wavelength, so keeping the 12" drivers next to the satellites will improve direct and reflected sound coherence around the room.

So, my idea with a separated cases (i mean with an different room position) for midbasses, is contrary with sound coherence?

What should be, if I will arrange 12"on a same(like a sattelites) height from floor, turn them on the one general with a sattelites direction line, and, of course, compensate range difference
with a time-delay? Some problems?
It looks like 12"midbass plays 1.2m right behind the satellites, through them (17" wavelenght quite itself has enough to round satellites boxes without problems). If we talk about different room reflections superposition for satellites & midbasses... I've try to make a sattelites sounds like in reflection-free room, and midbasses sounds like in-wall.
Really, I hope, this parts can go solid, with a necessary tune.

And why you talk about "below 60 Hz" applicable to an 12"? I prepared 18" Transmission-line to this part of spectre, 20-60 Hz.

Sorry, if my questions seems silly...
 
With a 200Hz crossover frequency, physically separating the 12" midbass from the TM satellites will generate very different room reflections with very different frequency vs. time delays and SPLs. Distortion, plus the Polar response will change. at your listening position. You cannot compensate for different room reflections. You cannot compensate for "lobe shifts" .

There are several AES papers with good study data which prove that a listener with trained hearing can physically locate the position of a woofer if the crossover frequency is over 60Hz. Even listeners with untrained hearing can physically locate the position of a woofer at 80Hz, which became the TDX standard for woofer + satellite speakers..
 
Thank you for reasoned answer!
Ok. Seems that in-corner placement is the only solution...

So, let's try:)

Can I made a 30-40" baffle width, or better try to minimize this size?
Why so big - because:
corner871d4.jpg

I can left my superchuncks to absorb LF, and can mount other absorption a joint in a joint with a speakers buffle. And I already have this sealed boxes:) Or it's not good idea?

Is it necessary to use 90H x 40V horn? Can I solve "room reflection on HF problem" by mounting sufficient absorption on front-side walls? So, I can mounth MF-HF absorption right on a speaker buffle, to prevent unwanted reflection :))

What about height of drivers placement? If take to the calculation, that I have "close to reflection-free" celling, may be there is a sense move drivers and listening position some upper, to decrease floor and table reflections? Or this can provide some problems with a floor SBIR of 12"...

Only experiements with a height position and mic can take me an answer, where should i cut:)
 
I do not think that corner placement is the best solution for a single listener, mixing music for typical customers. The distances are too long, and the ambience mix of direct/reflected does not match a normal home, such that your mixes would sound "bright" when played by your customers who hear more wall-bounce high frequencies.

If you do not have major plans to use this room for small group listening or HT, then your equilateral placement in post #13 using a pair of 3-way speakers should produce a good mix of direct sound plus some reflected ambience. Most people listening to your studio mix recordings in their homes will have a similar listening environment / experience.

I like the idea of "corner friendly" 3-way speakers where a portion of the cabinet sides are angled for improved performance with corner placement. You can pull these 3-way speakers into the room for normal single-person listening, or push these speakers into the corners for a small group audience. For the greatest flexibility, you could build a 12" woofer(midbass) bottom and use your current direct radiator speakers on top. This will allow FUTURE experiments with a 90H x 40V horn top, or even a 10" coaxial driver top. As Dr. Geddes discusses, you want to design for a smooth controlled directivity function. Naturally narrow polar response at high frequencies with a smooth widening transition to the baffle step frequency.
 

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The distances are too long,
13 feets.

If you do not have major plans to use this room for small group listening or HT,

I think, will be beautiful, if a can divide listening position with an people-two. And if i have more stable sound over the room. But it is'nt primary usage.
Primary usage - composing & mixing.
then your equilateral placement in post #13 using a pair of 3-way speakers should produce a good mix of direct sound plus some reflected ambience
Hmmm. My 3-way Sattelites cover down only to 150-200 Hz. In a #16 we solved that get midasses away from sats is a bad idea. So what you mean, when talk about "my equilateral placement"?:) I'm in confusion...
I like the idea of "corner friendly" 3-way speakers where a portion of the cabinet sides are angled for improved performance with corner placement.
Great! It's universal solution.
This will allow FUTURE experiments with a 90H x 40V horn top
.
okaaaay.... Now I understand, that is very important detail.

As Dr. Geddes discusses, you want to design for a smooth controlled directivity function. Naturally narrow polar response at high frequencies with a smooth widening transition to the baffle step frequency.
Does polar response so really matter, if I've going to absorb as many early reflections, as i can?
Why?

Thank again, I feel conducted through darkness, when i read your's answers.:)
 
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